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(No Model.)

B. M. POSTER.

DUMB WAITER. N0.'359,43.'7. Patented Mar. 15,- 1887.

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=N'ITED STATES PATENT Erica.

ELDRIDGE M. FOSTER, OF BALTIMORE, MARYLAND, ASSIGNOR OF ONEHALF 4 TO GILBERT O. BOLGIANO, OF SAME PLACE.

DUMB-WAITER.

SPECIFICATION forming part of Letters Patent No. 359,437, dated March 15, 1887, Application filed February 13, 1886. Renewed January 4, 1887. Serial No. 223.403. (No model.)

To all whom it may concern;

Be it known that I, Ennnrner. M. FOSTER, a citizen of the United States, residing at Baltimore, in the State of Maryland, have invented certain new and useful Improvements in Dumb- Waiters, of which the following is a specifica' tion.

Myinvention relates to hoisting mechanisui for a dumb-waiter; and it consists in the parts to and combinations hereinafter described and claimed.

The invention is illustrated in the accompanying drawings, in which- Figure 1 is a view of the hoisting mechan- 5 isms and dumb-waiter. Fig. 2 is an elevation of the spring-drum of the hoisting mechanism, one support or hearing being removed. Fig. 8 is a side view of the hoisting mechanism. Fig. 4 is a vertical section of the same.

Two supports, (2, have base-plates A, with screw-holes for attachment to the supportingwood 0. Between the two supports a drum, E, is mounted onahorizontal shaft, f. One side of the drum is open, (see Figs. 1 and 4,) and the drum forms an open chamber,which is occupied by a coiled spring, g. The drum has in its chamber a central hub, h, 011 which one end of the coiled spring gis secured,while the other end is made fast to a stud, 03, projecting laterally from one of the supports d into the side of the'open chamber. The spring is the power which turns the drum.

A stop-plate, It, is mounted on and keyed fast or otherwise rigidly secured to the shaft f near the open side of the drum. This plate has notches Z on its rim. In the present instance four notches are shown. A dog, r, is pivoted by a pin, 8, on the inner side of that support d which is adjacent to the said stop- 40 plate. Thus the dog has position between the said support d and the open chamber of the drum, and its pivot s is below the drunrshaft f. The dog has at one end a ing, t, for engagement with a notch, Z, on the stop-plate, and the other end, u, of the dog is weighted or made heavy enough to cause the lug end to press lightly upward and keep normally engaged with one of said notches. When the dog is in engagement with a notch on the stopplate, the spring-drum E and shaft f cannot turn, and the result is, the carriage F of the ing from the large end of the drum, as in Fig.

dumb waiter, hanging, as hereinafter described, by the cord G, will be sustained at whatever position it may have. As the notches,however, are shallow, the dog may readily be released therefrom, so as to permit the springdrum and shaft to turn, by first slightly raising the carriage F with an abrupt movement and then pulling 011 the cord H, which passes around the drum.

The spring-drum is provided at one side with a tapering winding-drum, I,whicl1 has a spiral groove, 1). In the present instance the spring-drum E and winding-drum I are shown as directly united; but it is obvious the winding-drum I may be separate, all that is necessary being that said winding-drum shall be fast to the shaft 1. The dumb-waiter cord G- is wound on the spiral groove of the tapering drum.

The tapering drum I, spring'drum E, carriage F, and cord G are so arranged and connected that when the carriage is down to its lowermost position the cord G will be hang- 3, and at such time the spring gwill be wound up to its greatest tension. \Vhen by the rotation of the drums the carriage F begins to go up, the spring has its greatest hoisting power, and the cord G will then commence to wind on the largest part of the tapered drum.

When the carriage is atits highest position, the cord G will be wound on the smallest part of the drum. The tapering drum, therefore, in hoisting compensates for the gradual weakening of the spring.

The cord II is fastened to the rim or face q of the spring-drum E, and is wound thereon as the carriage F ascends. This cord passes down to the basement, and when wound up its lower end, a, should be within reach of a person in the basement. As the diameter of the springdrum E (see Figs. 3 and 4.) is much more than that of the windingdrum I, it will be understood that the carriage F may be brought down with much less effort exerted in pulling on the cord II than would be necessary if the pull were made on the cord G. The cord H there fore serves to easily pull the carriage down, and removes an otherwise serious objection to the use of a spring-drum for hoisting.

I provide for automatically checking the descent of the carriage F, when it has reached the top, by means of a rubber strap or spiral spring, 20, which has one end secured to astationary device, m, at the basement and the other to the end 1) of the cord H. This elastic strap or spring will cause a gradually increased pull on the cord H, and thus gently stop the carriage just previous to its reaching the top, and such a device may be used on a dumbwaiter hoisted by means of a weight.

Having described my invention, I claim and desire to secure by Letters Patent of the United States 1. A spring-drum hoisting mechanism having, in combination, a spring-actuated drum, E, a notched stop-plate, a pivoted dog, a tapering winding-drum, I, having a spiral groove, a dumb-waiter carriage, F, and a cord connecting the said winding-drum and carriage, as set forth.

2. A spring-drum hoisting mechanism l|aving, in combination, a winding-drum, I, a dumb-waiter carriage, F, a cord, G, connecting the said winding-drum and carriage, and a spring-actuated drum, E, of greater diameter than the winding-drum and provided with a pull-down cord, H, which winds upon its face or rim, as set forth.

3. The combination of a winding-drum, a dumb-Waiter carriage, a cord connecting the said drum and carriage, and pull-down cord having its lower end secured to an elastic spring, w, whereby the ascent of the carriage will be checked just previous to its reaching the top, as set forth.

In testimony whereof I alfix my signature in the presence of two witnesses.

ELDRIDGE M. FOSTER.

lVitnesses:

JOHN E. Momns, JNo. T. MAnnoX. 

